CN112103159A

CN112103159A - X-ray tube housing with integral heat exchanger

Info

Publication number: CN112103159A
Application number: CN202010445853.1A
Authority: CN
Inventors: 凯里·S·罗杰斯; 阿努普·G·奈尔; 安德鲁·J·德罗齐埃; 锡德·拉杰; 卡西迪·C·什比亚
Original assignee: GE Precision Healthcare LLC
Current assignee: GE Precision Healthcare LLC
Priority date: 2019-06-17
Filing date: 2020-05-22
Publication date: 2020-12-18
Also published as: EP3764752A3; EP3764752A2

Abstract

The invention provides an X-ray tube housing with an integral heat exchanger. An x-ray tube housing includes an enclosure having a heat exchanger integrally formed thereon in an additive manufacturing process. The additive manufacturing process allows for tight tolerances with respect to the structure of the housing and the internal passages of the heat exchanger to significantly reduce the size and weight of the housing. The housing also includes a fluid distribution manifold that effectively distributes cooling fluid within the housing to more effectively provide cooling to the x-ray tube insert disposed within the housing.

Description

X-ray tube housing with integral heat exchanger

Technical field and background

The present invention relates generally to x-ray tubes, and more particularly to a housing for enclosing various components of an x-ray tube.

The X-ray system may include an X-ray tube, a detector, and a support structure for the X-ray tube and the detector. In operation, an imaging table on which an object is positioned may be positioned between the x-ray tube and the detector. The X-ray tube typically emits radiation, such as X-rays, toward the subject. The radiation passes through the object on the imaging table and impinges on the detector. As the radiation passes through the object, the internal structure of the object causes spatial differences in the radiation received at the detector. The detector then transmits the received data and the system converts the radiation differences into an image that can be used to assess the internal structure of the subject. The objects may include, but are not limited to, patients and inanimate objects in medical imaging protocols, such as packages in an x-ray scanner or a Computed Tomography (CT) package scanner.

The X-ray tube includes an X-ray tube insert and an X-ray tube housing. The x-ray tube insert is a functional device that generates x-rays, while the x-ray tube housing is an enclosure that surrounds, protects, and supports the insert. The x-ray tube housing performs the following functions:

physically supporting the x-ray tube insert within the x-ray tube housing such that an x-ray transmission window on the x-ray tube insert is maintained in a position aligned with the x-ray transmission window in the x-ray tube housing such that x-rays generated in the x-ray tube insert exit the x-ray tube assembly and illuminate an object of interest;

shielding x-rays emanating from the x-ray tube insert except for a defined portion that passes through the one or more x-ray transmission windows towards the object of interest;

-supporting a motor stator relative to a motor rotor for rotating the anode x-ray tube;

-providing a high voltage electrical connection between the x-ray tube insert and the high voltage generator, typically via a high voltage plug and socket or via a high voltage connector which is detachably secured to the high voltage insulator by a silicone washer;

-hermetically enclosing and directing the coolant within the x-ray tube housing around the x-ray tube insert-the vacuum vessel of the x-ray tube insert becomes hot in operation and this heat is removed by circulating dielectric oil or other suitable coolant over the x-ray tube insert vacuum vessel and subsequently pumped to an external heat exchanger where it is rejected back to room air or another liquid coolant and then back to the x-ray tube housing; and

-operatively connecting the x-ray tube insert to the imaging system gantry or positioner.

Referring to fig. 1 and 2, an x-ray tube insert 14 'is disposed within a conventional x-ray tube housing 10'. The housing 10 ' includes a shell 12 ', an end cap 15 ' secured to the shell 12 ' at one end, and a cover plate 16 ' secured to the shell 12 ' opposite the end cap 15 '. The enclosure 12 ' is formed by an intermediate housing 18 ' in which the x-ray tube insert 14 ' is disposed. The envelope 12 'also includes an end shell 21' connected to one end of the intermediate shell 18 ', which encloses the shaft of the x-ray source and the bearing assembly 14'.

The outer shell 12 ', such as the intermediate shell 18 ' and the end shells 21 ', are typically made by casting techniques, machined from bulk material, or made from separately formed parts that are joined together by welding and/or brazing processes. Subsequently, the intermediate shell 18 ' and the end shell 21 ' are engaged with one another to enclose the x-ray tube insert 14 ' positioned therein.

Referring now to fig. 1 and 2, the x-ray tube housing 10 'includes a heat exchanger 24' as part of a cooling circuit 25 'that utilizes a cooling system disposed outside the enclosure 12' and includes a water chiller/reservoir 27 'and a pump 29' that circulates cooling water through a dedicated oil to water heat exchanger 24 'to thermally contact and cool the dielectric tube oil 26' contained in the housing 10 'and pump through the opposite side of the heat exchanger 24'. The oil 26 ' passes through an oil filter 28 ' which retains the electrical insulating properties of the dielectric oil 26 '. As schematically shown in fig. 2, oil 26 ' is present within the housing 10 ' to support the x-ray tube insert 14 ' within the housing 10 ' and provide for heat removal from the insert 14 '.

While sufficient to cool the oil 26 ' from within the housing 10 ', the dedicated oil-to-water heat exchanger 24 ' and the associated cooling circuit 25 ' including the tubes or lines that direct the various fluids between the housing 12 ' and the heat exchanger 24 ' add increased cost, weight, and size to the x-ray tube housing 10 '. Furthermore, the size of the tube housing 10 ' including the heat exchanger 24 '/cooling circuit 25 ' connected to and/or mounted to the exterior of the housing 10 ' significantly increases the overall size and weight of the housing 10 ', which limits the degree of oblique imaging angles around the patient that can be utilized and can compromise the quality of the examination performed.

One attempt to overcome the problems associated with the external heat exchange circuit 25 is disclosed in co-pending and commonly owned U.S. patent application publication No. US2018/0376574, entitled X-Ray Tube casting, which is expressly incorporated herein by reference in its entirety. In this reference, the x-ray tube housing is formed in an additive manufacturing manner that forms fluid passages directly within the housing for counter flow of dielectric oil and cooling fluid to provide heat exchange between the fluids to cool the x-ray tube insert.

However, because the disclosed x-ray tube housing still employs multiple heat exchange circuit components external to the housing and has other problems, it is desirable to develop a structure, method of manufacture, and method of using an improved x-ray tube housing designed to reduce the weight of the housing while increasing the cooling capacity of the housing in use.

Disclosure of Invention

In the present invention, the x-ray tube housing provides both x-ray insert cooling and mechanical support without the need for a separate external cooling circuit. The housing is formed from metal in a suitable additive manufacturing process. The housing is formed to include a wall having an integral internal passage therein to supply cooling fluid directly to and through the housing body without the need for an external cooling circuit and/or a separate component heat exchanger.

According to one aspect of an exemplary embodiment of the present invention, the x-ray tube housing is made using a metallic material to form a structural wall of the enclosure that is continuous throughout the housing structure. This integral nature of the material forming the housing eliminates leakage that typically occurs at joints between component parts of prior art housings where the individual parts are joined or secured to one another. The wall thickness of the shell may vary during manufacture depending on the structural strength required at any particular location. This optimization provides the necessary amount of material at different locations in the housing while minimizing the overall mass of the housing.

According to another aspect of an exemplary embodiment of the present invention, the configuration of the housing with the cooling channels embedded within the housing provides the housing with the ability to direct chilled coolant through the housing and provide more efficient heat exchange due to the large surface area of the housing being in direct thermal contact with the dielectric oil flowing between the insert and the housing.

According to yet another aspect of an exemplary embodiment of the present invention, the ability to manufacture a housing with tight tolerances enables the formation of a housing that closely conforms to the shape of an x-ray tube insert. This enables the size of the oil gap between the housing and the x-ray tube insert to be reduced, which therefore enhances the contact of the oil with the insert for heat transfer purposes, and also provides improved dimensional stability to the insert when placed within the housing.

According to yet another aspect of an exemplary embodiment of the present invention, the housing includes a manifold disposed within the housing. The manifold provides a more efficient and uniform distribution of dielectric oil within the housing around the x-ray tube insert, thereby providing more efficient cooling of the x-ray tube insert. Cooling efficiency is improved by directing an integral split flow of available coolant to a preferential point of cooling on the insert. Due to the complexity of the internal coolant wiring, conventional x-ray tube housings do not contain deliberate cooling shunting and guiding.

According to a further aspect of an exemplary embodiment of the invention, the housing comprises means for accommodating volume expansion of the oil during operation of the x-ray tube insert. The member is formed as a deformable bladder or bellows located within the housing and movable upon heating under pressure exerted by oil expansion within the housing. The bladder serves to maintain a desired pressure exerted by the dielectric oil within the housing by increasing or decreasing the volume inside the housing to accommodate pressure changes due to temperature changes of the dielectric oil in the housing.

In another exemplary embodiment of the invention, the invention is an x-ray tube housing for an x-ray tube insert, the housing comprising an outer shell adapted to receive at least a portion of the x-ray tube insert therein, and a heat exchanger comprising a plurality of fluid flow passages, the heat exchanger formed on an outer surface of the outer shell, wherein the outer shell and the heat exchanger are formed in an additive manufacturing process.

In yet another exemplary embodiment of the present invention, an x-ray tube includes: an x-ray tube insert including a frame defining an enclosure; a cathode assembly disposed in the package; an anode assembly disposed in the enclosure spaced apart from the cathode assembly; and an x-ray tube housing comprising an enclosure formed in the additive manufacturing process and in which the x-ray tube insert is placed, the enclosure comprising a sidewall and a heat exchanger formed on an exterior of the sidewall.

In an exemplary embodiment of the method of the present invention, a method for exchanging heat from a cooling fluid disposed within an x-ray tube comprises the steps of: an additive manufacturing x-ray tube housing comprising an enclosure having a heat exchanger formed on an exterior surface of a sidewall of the enclosure, the heat exchanger comprising at least one passage in communication with an interior space defined by the enclosure; placing an x-ray tube insert in an interior space defined by a central frame; placing a quantity of cooling fluid in an interior space between the x-ray tube insert and the housing; and directing a flow of cooling fluid through the at least one passage to exchange heat from the cooling fluid.

It should be appreciated that the brief description above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.

Drawings

Fig. 1 is an isometric view of a prior art x-ray tube housing.

Fig. 2 is a schematic view of the prior art x-ray housing of fig. 1.

Fig. 3 is an isometric view of an x-ray tube housing according to an exemplary embodiment of the present invention.

Fig. 4 is an isometric view of an x-ray tube end housing according to an exemplary embodiment of the present invention.

Fig. 5 is a schematic view of the x-ray tube and x-ray housing of fig. 3.

Fig. 6 is a partially broken away isometric view of the x-ray tube end housing of fig. 4.

Fig. 7 is a partially broken away isometric view of the x-ray tube end housing of fig. 4.

Fig. 8 is a partially broken away cross-sectional view of the x-ray tube end housing of fig. 4.

Fig. 9 is a cross-sectional view taken along line 9-9 of fig. 4.

Fig. 10 is a partially broken away cross-sectional view of the x-ray housing of fig. 9.

Fig. 11 is an isometric view of an x-ray tube housing according to another exemplary embodiment of the invention.

Fig. 12 is a top plan view of the x-ray tube housing of fig. 11.

Detailed Description

In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments which may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments, and it is to be understood that other embodiments may be utilized and that logical, mechanical, electrical and other changes may be made without departing from the scope of the embodiments. The following detailed description is, therefore, not to be taken in a limiting sense.

Referring now to fig. 3 and 4, in the exemplary embodiment shown, an x-ray tube insert (not shown) is disposed within an x-ray tube housing 100 to form an x-ray tube 11. The casing 100 includes a hollow housing or body 102, a High Voltage (HV) connector/end cap 104 secured to the housing 102 adjacent the cathode assembly (not shown), and a cover plate 106 secured to the housing 102 opposite the HV connector 104 (fig. 10). The hollow enclosure 102 is formed by a generally cylindrical intermediate casing 108 which is open at each

end

107, 109 and in which the cathode assembly and anode (not shown) of the x-ray tube 11 are disposed. The enclosure 102 also includes a generally cylindrical end housing 110 that is mounted to and/or disposed about one open end 109 of the intermediate housing 108, which itself includes an open port 111 opposite the intermediate housing 108, and encloses the shaft 61 and bearing assembly 63 (fig. 9) of the x-ray source (not shown) extending outwardly from the intermediate housing 108.

Referring now to the exemplary embodiment shown in fig. 3-4, end housing 110 additionally encloses a stator basket (not shown) disposed inside end housing 110 about shaft 61 and bearing assembly 63. The stator basket is operatively connected to a voltage source (not shown) via a suitable connector (not shown) that extends through an aperture 116 in the end housing 110 to supply current to the stator basket to enable the basket to interact with and rotate the shaft 61 when the x-ray tube insert is operated.

Referring now to the exemplary embodiment shown in fig. 9-10, the open end 111 of the end housing 110 is enclosed by a cover plate 106 that is engaged with a flexible bladder or fluid expansion bellows 117 that is engaged between the cover plate 106 and the open end 111 of the end housing 110. The bellows 117 is formed from a suitable material, such as a rubber bladder, and extends over the entire open end 111 of the end housing 110. In the exemplary illustrated embodiment, the bellows 117 is generally circular in shape and includes a curved cross-section to provide the bellows 117 with the ability to expand and contract under a pressure differential applied across the bellows 117. To maintain a fluid-tight seal with the cover plate 106 and the end housing 110, the bellows 117 includes a peripheral cylindrical bead 118 formed around the entire periphery of the bellows 117. The bead 118 is disposed within and compressed by aligned

complementary grooves

120, 122 formed in the cover plate 106 and the end housing 110, respectively, to provide a fluid-tight seal while also allowing the bellows 117 to expand and contract between the cover plate 106 and the end housing 110. To accommodate expansion and contraction, the cover plate 106 includes a vent 124 that allows air to enter and exit a space 126 defined between the bellows 117 and the cover plate 106.

Opposite the cover plate 106, the end housing 110 is secured to the intermediate housing 108 in a suitable manner to seal the end housing 110 to the intermediate housing 108. With the end housing 110 so sealed, it is possible to fill the end housing 110 with an amount of dielectric oil 136, such as via a sealable oil fill port 139, to provide cooling for operation of the shaft 61 and bearing assembly 63.

As shown in the exemplary embodiment of fig. 5, when assembled with the HV connector/end cap 104 and the cover plate 106, the housing 102 defines an interior space (not shown) in which the portion of the x-ray tube insert including the cathode assembly and the anode/target 56 are located. The middle shell 108 and the end shells 110 of the outer shell 102 effectively form a fluid-tight enclosure around the interior space 134 to retain a quantity of cooling fluid/dielectric oil 136 in the interior space 134 between the x-ray tube insert/source 14 and the outer shell 102. The oil 136 is introduced through a sealable fill port 139 formed in the end housing 110 and is used to cool the internal components of the x-ray tube insert 14 by flowing through and in thermal contact with the frame 50 surrounding the x-ray tube/source 14 and extracting heat generated by operation of the x-ray tube insert 14 from the x-ray tube insert 14 through contact with the frame 50.

Referring now to fig. 4-8, to remove heat from the insert cooling fluid/dielectric oil 136, the shell 100 or one or more components of the shell 100, such as the entire shell 102, the middle shell 108, the end shells 110, the end caps 104, or any combination thereof, may be formed to include one or more passageways 138 or

channels

152, 154 therein to enable the cooling fluid 140 to pass through the sidewalls 121 of the shell 100 or components thereof. This provides an integral cooling function for the housing 100 such that the housing 100 can effectively remove heat generated by the operation of the shaft 61 and the bearing assembly 63.

In one exemplary embodiment, schematically illustrated in fig. 5, one or more passageways 138 may be formed as a continuous passageway 138 through the sidewall 121 of the housing 102 or a portion thereof, or may be formed as separate passageways 138, each extending through the sidewall 121. The one or more passages 138 are each connected to a source of cooling fluid 140, such as water, a water/glycol mixture, or any other suitable fluid having desired heat exchange characteristics, that is directed into the passages 138 to flow from the inlet header 142, 157 to the outlet header 144, 159 of each passage 138. The heat transfer characteristics of water are significantly better than dielectric oil, so the total heat transfer depends on the heat transfer from the vacuum vessel wall/frame 50 to the oil 136. Each passageway 138 is formed within the sidewall 121 to maintain a thickness of the sidewall 121 between the interior space 134 of the housing 102 and the passageway 138 that is sufficient to allow cooling fluid 140 flowing through the passageway 138 to thermally contact the oil 136 located within the interior space 134, but not to allow the oil 136 and the fluid 140 to directly contact each other. This provides for efficient heat exchange due to the large surface area of the sidewall 121 being in direct contact with the dielectric oil 136 flowing in the space or gap 180 between the x-ray tube insert 14 and the sidewall 121. The cooling fluid 140 may be introduced into the inlet end 142 of the passageway 138 by a pump 146 connected to a chilled reservoir 148 of the cooling fluid 140 that is used to cool the heated cooling fluid 140 exiting the passageway 138 in the housing 102. The operation of the pump 146 may be controlled to direct the cooling fluid 140 into the passageway 138 at a rate commensurate with the operation of the x-ray tube 14 to provide the appropriate cooling to the dielectric oil 136.

The dielectric oil 136 may be brought into thermal contact with the cooling fluid 140 in one or more passageways 138 solely by convection, in which case heat absorbed by the oil 136 adjacent the frame 50 moves the heated oil 136 outwardly from the frame 50, with heating through the interior space 134 toward the housing 102. Upon reaching the enclosure 102, the heated oil 136 is in thermal contact with a cooling fluid 140 flowing through one or more passages 138 to cool the oil 136, which then flows back to the frame 50 to move the heated oil 136 proximate to the frame 50. This embodiment is suitable for lower average power x-ray tubes 14 used on surgical C-arms and further reduces cost, size and weight due to the elimination of the oil pump 150.

Alternatively, the oil 136 may be circulated into thermal contact with the cooling fluid 140 by a pump 150 that draws the heated oil 136 from the interior space 134 via a suitable conduit connected to an outlet header 153 and through an oil filter 149, and then reintroduces the oil 136 from the filter 149 into the interior space 134 of the housing 102 through an inlet header 155 via a suitable conduit. In this way, the oil 136 is brought into thermal contact with a cooling fluid 140 flowing through one or more passages 138 to cool the oil 136.

With particular respect to the exemplary embodiments shown in fig. 4 and 6-8, the housing 100 or component parts of the housing 100, such as the entire shell 102, the middle housing, the end housing 110, or any combination thereof, may be formed with

internal counterflow channels

152, 154 separated by plates 151 and extending through the side walls 121 of the end housing 110/component parts of the housing 100 in place of the passages 138. As shown with respect to the end housing 110, the

channels

152, 154 and the plates 151 are located within a unitary heat exchanger 160 that is directly on the exterior of and integrally formed with the side wall 121 of the end housing 110.

As shown in the exemplary embodiment shown in fig. 6 and 7, in the heat exchanger 160, a passage 152 is connected between an oil inlet header 153 and an oil outlet header 155 for providing a first flow path 156 for the heated dielectric oil 136. The oil 136 is drawn from the outlet header 155 via a suitable conduit connected to a pump 150, which may be provided directly in a pump chamber or housing 170 (fig. 11-12) on the end housing 110, for drawing the heated oil 136 from the interior 134 of the end housing 110. Additionally, the end housing 110/heat exchanger 160 may be formed to additionally integrally connect the oil outlet header 155 with the manifold 164 to direct the cooled oil 136 back into the interior 134 of the housing 100. In the exemplary embodiment shown in fig. 11 and 12, the housing 170 is integrally formed with the remainder of the end housing 110, such as in an additive manufacturing process, and includes oil and oil inlets formed therein. In this way, the oil inlet 153 and the oil outlet 155 are eliminated from the end housing 110, further reducing the number of hoses and other connections required for operation of the tube 11.

Furthermore, as shown in the exemplary embodiment shown in fig. 12, a passage 154 is connected between an oil inlet header 157 and an outlet header 159 to provide a second counterflow path 158 for cooling fluid/water 140 that is directed from the reservoir 148 to and from the passage 154 through suitable conduits connected to the pump 146. While any configuration of the

channels

152, 154 is considered to be within the scope of the present invention, as shown in the exemplary embodiment of fig. 8, one or both of the

channels

152, 154 may be made as a plurality of conduits 161 separated by fins 162 to increase thermal contact and consequent heat transfer between the oil 136 and the cooling fluid 140 flowing through the

channels

152, 154. These

channels

152, 154 may also be made with an angular slope to provide additional structural integrity to the

channels

152, 154. In addition, the number of conduits 161 formed in the

respective channels

152 and 154 may be formed to be the same or different from each other in order to achieve a desired heat exchange within the heat exchanger 160 including the

channels

152, 154.

Referring now to the exemplary illustrated embodiment of fig. 9 and 10, the cooled dielectric oil 136 exiting the oil exit header 155 is introduced into a fluid distribution manifold 164 disposed within the end housing 110 adjacent the bellows 117, and in the exemplary embodiment shown is integrally formed with the end housing 110. The manifold 164 extends within the interior of the end housing 110 and includes a plurality of spaced nozzles or

apertures

166, 168 extending therethrough. The holes 166 are located at the periphery of the manifold 164 and are used to direct a quantity of the cooled dielectric oil 136 into the interior 134 of the end shell 110 where the oil 136 may be in thermal contact with the frame 50 of the x-ray tube insert 14. A bore 168 is generally centrally located on the manifold 164 in alignment with the bearing assembly 63 to direct a quantity of cooled dielectric oil 136 into the shaft 61 and the bearing assembly 63.

Because the passageway 138 or

channels

152, 154 are formed directly in the sidewall 121 of the housing 100, a manufacturing process with tight tolerance control is required to form the housing 100. To reduce costs, reduce weight, and provide the complex formed sidewalls 121 with internal passageways 138 or

channels

152, 154 as described above, the shell 100/shell 102/intermediate shell 108/end shell 110 may be manufactured or formed at least partially or entirely via one or more additive manufacturing techniques or processes, thereby providing greater accuracy and/or more complex details within the shell 100/shell 102/intermediate shell 108/end shell 110 than previously producible by conventional manufacturing processes. As used herein, the term "additive manufacturing" or "additive manufacturing technique or process" includes, but is not limited to, various known 3D printing manufacturing methods, such as extrusion deposition, wire, particulate material bonding, powder bed and inkjet head 3D printing, lamination, and photopolymerization.

In one embodiment, the additive manufacturing process of Direct Metal Laser Melting (DMLM) is an exemplary method of manufacturing the shells 100/shell 102/middle shell 108/end shell 110 or components thereof described herein. DMLM is a known manufacturing process that uses three-dimensional information to make three-dimensional computer models of metal parts, such as shell 100/shell 102/middle shell 108/end shell 110. The three-dimensional information is converted into a plurality of slices, wherein each slice defines a cross-section of the component for a predetermined height of the slice. The shell 100/shell 102/middle shell 108/end shell 110 (such as the sidewall 121 of the end shell 110) is then "stacked" piece-by-piece or layer-by-layer until complete. Each layer of the shell 100/shell 102/middle shell 108/end shell 110 is formed by fusing or fusing layers of metal powder (such as aluminum powder) or other material/metal (such as stainless steel) to each other using a laser.

Although the method of manufacturing the shell 100/shell 102/middle shell 108/end shell 110 including the internal passageways 138 or

channels

152, 154 has been described herein using DMLM, one skilled in the art of manufacturing will recognize that any other suitable rapid manufacturing method utilizing layer-by-layer construction or additive manufacturing may also be used. These alternative rapid manufacturing methods include, but are not limited to, Direct Metal Laser Sintering (DMLS), Selective Laser Sintering (SLS), 3D printing (such as by inkjet and laser inkjet), stereolithography (SLS), Direct Selective Laser Sintering (DSLS), Electron Beam Sintering (EBS), Electron Beam Melting (EBM), Laser Engineered Net Shape (LENS), Laser Net Shape Manufacturing (LNSM) electron beam powder bed fusion, and Direct Metal Deposition (DMD).

Due to the precise manufacturing tolerances provided by manufacturing the housing 100 using an additive manufacturing process, the width and/or height of the passages 138 or

channels

152, 154 may be formed to be between 1.0mm to 2.0mm, and in other embodiments between 1.4mm to 1.8mm, within the heat exchanger 160. Furthermore, precise control of the overall shape of the housing 100, including the intermediate housing 108 and the end housing 110, relative to the shape of the x-ray tube insert 14, allows for a reduction in the size of the oil gap 180 between the frame 50 of the x-ray tube insert 14 and the sidewall 121 of the housing 100, thereby significantly increasing the heat transfer coefficient compared to conventional x-ray housings by maintaining a small oil layer/gap 160 hydraulic diameter.

Furthermore, while the additive manufacturing process used to construct the housing 100 (e.g., the end housing 110) allows for precise manufacturing tolerances, the nature of the material or materials used in these processes results in the surface of the end housing 110 being relatively rough or uneven. Thus, these uneven or rough surfaces within the passages 138 or

channels

152, 154 further enhance the heat exchange characteristics of the heat exchanger 160 including the passages 138 or

channels

152, 154 due to the increased surface area within the passages 138 or

channels

152, 154 from the rough surfaces.

Bonding heat exchanger 160 directly to end shell 110 allows for a significant reduction in the size and weight of x-ray tube 12, including insert 14 and shell 100, through the additive manufacturing process of shell 100 and/or its constituent components, such as the entire enclosure 102, intermediate shell 108, and/or end shell 110 in particular. The end housing 110 structurally incorporates a number of previous external or additional components into the end housing 110 to accomplish this and eliminate a number of connecting hoses, seals and potential leak points created. End housing 110 also provides directional cooling to insert 14 and bearing assembly via manifold 164, and accommodates expansion of oil 136 internally through the use of bellows 117, all within the structure of end housing 110.

Due to this improved structure of the housing 100, and in certain exemplary illustrated embodiments the end housing 110, the smaller and lighter x-ray tube 11 improves the angle of the tube 11 around the patient to improve the viewing angle and provide better treatment. Furthermore, the x-ray tube 11 occupies a smaller area, better access to the patient and can reduce the static and dynamic loading of the C-arm, thereby enabling faster rotational speeds and lower gantry costs.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. An x-ray tube housing for an x-ray tube insert, the housing comprising:

-a housing adapted to receive at least a portion of the x-ray tube insert therein, and;

-a heat exchanger comprising a plurality of fluid flow passages, the heat exchanger being formed on an outer surface of the housing,

-wherein the housing and the heat exchanger are formed in an additive manufacturing process.

2. The x-ray tube housing of claim 1, wherein the plurality of fluid flow passages comprises a first fluid flow passage and a second fluid flow passage.

3. The x-ray tube housing of claim 2, wherein the first fluid flow path and the second fluid flow path are counter-current to each other.

4. The x-ray tube housing of claim 2, wherein the first fluid flow passage and the second fluid flow passage are of different sizes.

5. The x-ray tube housing of claim 2, wherein one of the first or second fluid flow paths is in fluid communication with an interior space of the housing.

6. The x-ray tube housing of claim 1, further comprising a fluid distribution manifold disposed within an interior of the enclosure.

7. The x-ray tube housing of claim 6, wherein the manifold is integrally formed with the housing.

8. The x-ray tube housing of claim 1, wherein the enclosure comprises an oil pump chamber formed on the exterior of the enclosure.

9. The x-ray tube housing of claim 8, wherein an oil pump housing is in fluid communication with the plurality of fluid passages in the heat exchanger.

10. The x-ray tube housing of claim 1, further comprising a fluid expansion bellows disposed within the enclosure.

11. The x-ray tube of claim 10, wherein the bellows comprises a peripheral sealing bead engaged with the housing.

12. The x-ray tube housing of claim 1, wherein the housing comprises:

-an intermediate housing in which at least a portion of the x-ray tube insert is disposed; and

-an end housing secured to the intermediate housing in which at least a portion of the x-ray tube insert is disposed, the end housing including the heat exchanger having a plurality of fluid flow passages formed on an outer surface of the end housing.

13. An x-ray tube comprising:

-an x-ray tube insert; and

-an x-ray tube housing comprising an enclosure formed in an additive manufacturing process and in which the x-ray tube insert is placed, the enclosure comprising a side wall and a heat exchanger formed on an exterior of the side wall.

14. The x-ray tube of claim 13, wherein the heat exchanger comprises:

-a first internal passage having an inlet and an outlet, wherein the first internal passage is not in fluid communication with an internal space defined by the housing; and

-a second internal passage having an inlet and an outlet, wherein the second internal passage is in fluid communication with the internal space defined by the housing.

15. A method for exchanging heat from a cooling fluid disposed within an x-ray tube, the method comprising the steps of:

-an additive manufacturing x-ray tube housing comprising an enclosure having a heat exchanger formed on an outer surface of a sidewall of the enclosure, the heat exchanger comprising at least one passage in communication with an interior space defined by the enclosure;

-placing an x-ray tube insert within an interior space defined by a central frame;

-placing a quantity of cooling fluid in an interior space between the x-ray tube insert and the housing; and

-directing a flow of the cooling fluid through the at least one passage to exchange heat from the cooling fluid.